不锈钢薄板高速激光焊驼峰焊道形成倾向及其影响因素  

STUDY OF HUMPING TENDENCY AND AFFECTING FACTORS IN HIGH SPEED LASER WELDING OF STAINLESS STEEL SHEET

作　　者：裴莹蕾[1] 单际国[1,2] 任家烈[1] 

机构地区：[1]清华大学机械工程系,北京100084 [2]清华大学先进成形制造教育部重点实验室,北京100084

出　　处：《金属学报》2012年第12期1431-1436,共6页Acta Metallurgica Sinica

摘　　要：研究了SUS304不锈钢薄板光纤激光焊接时激光功率、焊接速度、保护气对焊道驼峰倾向的影响规律,利用Ti示踪元素和CCD图像,考察了熔池的流动状态.结果表明,焊道驼峰倾向对激光功率不敏感;当焊接速度超过18 m/min时,焊缝出现驼峰现象,且驼峰倾向随着焊接速度的提高而增大;当焊接速度和功率一定时,不同保护气流方向的焊缝驼峰倾向有明显差异,与焊接方向同向吹送保护气有助于降低驼峰倾向.分析认为,焊接速度的提高使熔池流动更加剧烈,进而增加了驼峰倾向;与焊接方向反向吹送保护气体,焊缝几何形状呈"柱状",与焊接方向同向吹送保护气体,焊缝的几何形状呈"杯状","杯状"焊缝增加了U形区域的截面积,降低了熔池流动的剧烈程度,进而降低了驼峰倾向.通过调整保护气流方向改变焊缝的几何形状以增加U形区域的截面积,是降低驼峰倾向的可行途径.The fiber laser was used to weld austenitic stainless steel SUS304 sheet at the speed of 24 m/min. The effects of laser power, welding speed and shielding gas on humping tendency have been investigated. The melt flow in the molten pool under different welding parameters was studied by Ti tracer method and CCD visual detection system. The results show that the humping tendency is not sensitive to the laser power. The humping is formed when welding speed exceeds 18 m/min, and goes up with the increasing of welding speed. The humping tendency is completely different as changing the direction of shielding gas under constant welding speed and laser power, and it is reduced when the shielding gas direction follows the welding direction. It can be explained that, with the increasing of welding speed, the melt flow becomes fierce, and the humping tendency goes up. The weld shape turns to the ＂columnar weld＂ , when the shielding gas direction against the welding direction; the weld shape turns to the ＂cup weld＂ when the shielding gas direction follows the welding direction. The ＂cup weld＂ expanded ＂U area＂ which gentles the melt flow and reduces humping tendency. Therefore, adjusting the shielding gas direction to expand the ＂U area＂ is an effective approach to reduce the humping tendency.

关 键 词：高速激光焊 驼峰倾向 熔池流动 焊接工艺 奥氏体不锈钢 

分 类 号：TG456.7[金属学及工艺—焊接]